It has become common to provide sophisticated electronically-controlled equipment, which is going to be used by highly-capable, easily-instructed users, with the technological means to determine what is wrong when the users sense that the equipment is not operating properly.
The user determination can be the first step in quickly overcoming an equipment malfunction so the user's work may proceed with scarcely a ripple.
A place one may see this technique used to great advantage is with modern xerographic photocopying machines, where, when some malfunction or matter needing remedial attention develops, the machine ceases producing copies, and in its L.E.D. display which normally visibly tallies the copies being made, a code appears. Upon consulting a chart provided with the copier, the user may equate the code to a particular act of repair or remedial procedure which is to be conducted.
Many of these acts and procedures are ones which may be executed on the spot by the normal, highly-capable user of the copies. Thus, the machine may be returned to service by the user after only a few moments of "down" time, and a service call to the manufacturer or service supplier of the machine is avoided. This makes life much easier for both the user of the machine and the manufacturer or service supplier. Even if the user is not equipped to make the indicated repair, he or she often is enabled to indicate when placing a service call exactly what the machine indicates is its problem.